Sliding component

Abstract

A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

The invention claimed is:  
     
       1. A sliding component characterized in that a positive pressure generating mechanism comprising a positive pressure generating groove is provided to an internal high-pressure peripheral side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, a negative pressure generating mechanism comprising a negative pressure generating groove is provided to an external low-pressure peripheral side, and a pressure release groove is provided between said positive pressure generating groove and said negative pressure generating groove, said positive pressure generating groove, said pressure release groove, and said negative pressure generating groove being communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface on the external peripheral side. 
     
     
       2. A sliding component according to  claim 1 , characterized in that said pressure release groove is provided to each of said two sliding surfaces so as to be positioned between said positive pressure generating groove and said negative pressure generating groove. 
     
     
       3. The sliding component according to  claim 1 , characterized in that the external-peripheral-side positive pressure generating mechanism is formed from a Rayleigh step mechanism, the internal-peripheral-side negative pressure generating mechanism is formed from a reverse Rayleigh step mechanism, and the pressure release groove is formed from a circular groove, said Rayleigh step mechanism, said reverse Rayleigh step mechanism, and said pressure release groove all being communicated with the high-pressure fluid side. 
     
     
       4. The sliding component according to  claim 3 , characterized in that pluralities of Rayleigh step mechanisms n and pluralities of reverse Rayleigh step mechanisms n are provided in parallel in a circumferential direction to either side of the pressure release groove so as to constitute pairs, and an upstream end of a groove part of an n th  Rayleigh step mechanism and a downstream end of a groove part of an n−1 th  reverse Rayleigh step mechanism are formed so as to substantially coincide in a position in the circumferential direction as seen from the upstream side, both groove parts and the pressure release groove being connected with the high-pressure fluid side via a shared communication groove. 
     
     
       5. The sliding component according to  claim 3 , characterized in that said plurality of reverse Rayleigh step mechanisms are provided in a radial direction. 
     
     
       6. The sliding component according to  claim 1 , characterized in that the width of the internal-peripheral-side seal surface can be varied. 
     
     
       7. The sliding component according to  claim 1 , characterized in that a radial-direction groove is shaped so as to be slanted from the internal peripheral side communicated with the negative pressure generating mechanism to the external peripheral side in the rotational direction of the counterpart sliding surface. 
     
     
       8. A sliding component characterized in that an external peripheral side of a pair of sliding components is a high-pressure fluid side, an internal peripheral side is a low-pressure fluid side, a positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of a sliding surface of a stationary-side sliding component, a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side of a sliding surface of a rotating-side sliding component, and a pressure release groove is provided to each of said stationary-side and rotating-side sliding surfaces so as to be positioned between said positive pressure generating groove and said negative pressure generating groove, said positive pressure generating groove, said pressure release grooves, and said negative pressure generating groove being communicated with the high-pressure fluid side and separated from the low-pressure fluid Side by a seal surface on the external peripheral side. 
     
     
       9. A sliding component characterized in that a pair of sliding components comprise annular bodies, an external peripheral side of the annular bodies is a high-pressure fluid side and an internal peripheral side is a low-pressure fluid side, a positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of a sliding surface on one side of the annular body, a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side, and a pressure release groove is provided between said positive pressure generating groove and said negative pressure generating groove, said positive pressure generating groove, said pressure release groove, and said negative pressure generating groove being communicated with the high-pressure fluid side and separated from the low-pressure fluid side by a seal surface on the external peripheral side. 
     
     
       10. A sliding component according to  claim 9 , characterized in that said positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side in a stationary-side sliding surface of the annular body, said negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side of a rotating-side sliding surface of the annular body, and a pressure release groove is provided to said stationary-side and rotating-side sliding surfaces so as to be positioned between said positive pressure generating groove and said negative pressure generating groove, said positive pressure, generating groove, said pressure release grooves, and said negative pressure generating groove being communicated with the high-pressure fluid side and separated from the low-pressure fluid side by a seal surface on the external peripheral side.